Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
83 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What are pollen grains |
They are partially germinated microspores which represent the male gametophyte of a sporophyte |
|
|
|
What are the cells present in a pollen grain |
Vegetative and generative cell |
|
|
|
Which of the two cells in a pollen grain produces the pollen tube |
The vegetative cell |
|
|
|
From where does the pollen tube obtain it’s nourishment during growth |
From the transmitting tissue of the style during its growth |
From a part of the carpel |
|
|
What is the role of pollen tube in the reproduction of flowering plants |
Carries make gametes to female gamete for fertilisation |
|
|
|
Which layer of the pollen wall grows out as a pollen tube |
Intine |
|
|
|
What stimulates the germination of pollen grain |
Sugary substance present on stigma |
|
|
|
What is the shape of a pollen grain |
It is roughly globular in outline, though other shapes are also found |
|
|
|
What is palynology |
The study of pollen is called palynology |
|
|
|
What is the composition of the cell wall of pollen grain |
It is made of two layers, intine and exine |
|
|
|
What is the composition of the wall of pollen grain |
Intine is made of pecto-cellulose Exine is made of a highly resistant fatty substance called sporopollenin |
|
|
|
What are the thing regions in exine called and what is their function |
They are called aperture or germ pore and it is the region where the pollen tube comes out of the pollen grain |
|
|
|
What is tectum |
It is the discontinuous surface layer around the exine, which provides characteristic sculpturing or designs over the surface of the pollen grain |
|
|
|
What is the importance of a tectum to a taxonomist |
It can help a taxonomist identify the pollen grain and determine its family, genus or species |
|
|
|
What is gametogenesis |
Gametogenesis is the process by which make and female gametes, sperm and ova are produced in the testis and ovary respectively |
|
|
|
What is spermatogenesis |
Spematogenesis is the process of formation of sperms in the testis |
|
|
|
What is oogenesis |
The process of formation of ova in the ovary |
|
|
|
What are the main parts of a spermatozoa |
A typical mammalian spermatozoa consists of a head, neck, middlepiece and tail |
|
|
|
At what stage is the human ovum released from the ovary |
The ovum is released from the ovary in the secondary oocyte stage |
|
|
|
What is meiosis |
Meiosis is a double division which occurs in diploid cells and gives rise to four haploid cells, each having half the number of chromosomes as compared to the parent cell. |
|
|
|
At what stage of meiosis does crossing over take place |
Pachytene stage in prophase-1 |
|
|
|
What is crossing over |
It is the process of exchange of chromatid segments between non-sister chromatids of homologous chromosomes during pachytene stage of meiosis 1 |
|
|
|
What is the significance of meiosis |
It is responsible for recombination of paternal and maternal genes in the gametes |
|
|
|
In which cells of testis meiosis takes place |
In spermatocytes |
|
|
|
What is spermatogenesis |
It is the process of formation of sperms in the testis |
|
|
|
What is the significance of meiosis during sperm formation |
Meiosis reduces the chromosome number to half in sperm. It maintains the chromosome number constant in sexually reproducing organisms |
|
|
|
Do you expect to find same number of chromosomes in testis of grasshopper and other organisms? |
No, each species has different number of chromosomes |
|
|
|
Why is meiosis 1 known as reductional division |
It reduces the number of chromosomes in a cell from diploid to haploid |
|
|
|
Why is meiosis II known as equational division |
Meiosis II is similar to mitosis and separates the two chromatids of each chromosome and thus, the daughter cells have the same number of chromosomes |
|
|
|
What is cleavage |
It is a series of rapid mitotic divisions of the zygote which convert the single celled zygote into a multicellular structure called a blastula or a blastocyst |
|
|
|
What is morula |
The solid mass of cells formed after cleavage is called morula |
|
|
|
What is blastocyst |
It is a stage of embryonic development consisting of an outer envelope of cells, the inner cell mass and a fluid filled cavity called blastocoel |
|
|
|
What is implantation |
It is the attachment of the blastocyst to the uterine wall |
|
|
|
When does implantation occur in human beings |
It occurs 7 days after fertilization |
|
|
|
What was mendels experimental material? |
Garden pea (pisum sativum) |
|
|
|
Why pea plant was a good selection by Mendel in formulating laws of heredity |
1) many pairs of contrasting characters 2) short life cycle 3) self pollinating and could easily be cross pollinated when required 4) characters are easy to see |
|
|
|
On sowing round seeds of pea, wrinkled seeds also appeared in the progeny. What does this indicate? |
Appearance of wrinkled seeds in the progeny proves that round seeds were hybrid. Round shape is dominant over wrinkled shape. |
|
|
|
If you are given a tall pea plant, how would you find it’s genotype? Explain |
The genotype of a tall pea plant can be known by a test cross. The homozygous tall plant will produce all tall plants while the heterozygous tall plant will produce both tall and dwarf plants in the ratio 1:1 |
|
|
|
Why Mendel got success while his predecessors failed to discover the basic principles of inheritance |
1) studied inheritance of each character separately 2) maintained a careful and accurate record of every cross and analysed the data statistically 3) selected garden pea 4) got expectable results |
|
|
|
How many pairs of contrasting characters did Mendel select for his study |
Seven |
|
|
|
What is phenotype |
The external manifestation of the genotype in an organism is called phenotype |
|
|
|
What is genotype |
The genetic makeup of an organism is called its genotype |
|
|
|
What is meant by Pedigree |
A diagrammatic record of inheritance of a particular trait/traits over two or more generations in a family tree |
|
|
|
What is Pedigree analysis |
It is analysis of diagrammatic record of inheritance of a particular trait/traits over two or more generations in a family tree |
|
|
|
What is the importance of a pedigree analysis |
It helps in knowing the possibility of presence of a trait in homozygous or heterozygous state in particular offspring |
|
|
|
What is the source of infection of amoebiasis |
It is a water borne disease |
|
|
|
What is the most important diagnostic feature of entamoeba histolytica |
It has a single pseudopodium |
|
|
|
What is digenetic life cycle |
Digenetic life cycle is the life cycle of a parasite which completes in two hosts Eg: plasmodium |
|
|
|
Name the oldest drug used in the treatment of malaria |
Quinine |
|
|
|
Name some anti-malarial drugs |
Quinine, chloroquinine, camoprima, camoquin |
|
|
|
How can the disease ascariasis be treated |
By administering anti helminthic drugs like oil if dewormis, wormin, zentel, etc |
|
|
|
What are xerophytes |
The plants which have adaptations to xeric habitats |
|
|
|
What are xeric habitats |
Habitats where soil does not hold much water and the environmental conditions are arid |
|
|
|
What are ephemerals |
Ephemerals are drought escaping plants which grow during the short rainy season and complete their life cycle before the habitat becomes dry |
|
|
|
What are succulent xerophytes |
These are drought resisting xerophytes, which resist drought by storing large amounts of water during rainy season |
|
|
|
What are xerocoles |
The animals which live in dry or xeric habitats are called xerocoles |
|
|
|
What are hydrophytes |
The plants that grow in abundance of water are called hydrophytes |
|
|
|
What are the main stresses faced by the hydrophytes |
Abundance of water, decifiency of light and oxygen, tearing and decaying effect of water |
|
|
|
What is the function of aerenchyma in hydrophytes |
It stores air which is utilised by plants tissues in metabolism |
|
|
|
What are the functions of swim bladder in fresh water fish |
The swim bladder stores air which help the fish to stay in water at a required depth without expending energy (helps in buoyancy) |
|
|
|
What is soil |
Soil is the upper weathered and humid containing layer of the earth which sustains plant life and contains numerous living organisms |
|
|
|
What is meant by soil texture |
Soil texture refers to the relative proportions of different types of soil particles in the soil |
|
|
|
What is humus |
It is a dark coloured amorphous substance composed of organic matter in different stages of litter-decomposition |
|
|
|
What is litter |
Fallen leaves and twigs of trees and other vegetable materials form the litter |
|
|
|
What are major types of soil particles |
Sand, silt and clay |
|
|
|
What is the term used for the scientific study of soil |
Pedology |
|
|
|
Which kind of soil is best suited for plant growth |
Loamy soil |
|
|
|
What is clay soil? |
The soil which has high percentage of clay particles |
|
|
|
What is meant by soil reaction |
Soil reaction denotes the pH of the soil |
|
|
|
What determines the pH of a soil? |
It depends on the relative amount of absorbed H+ ions or metallic cations Ca2+, Mg2+ etc.) |
|
|
|
What pH range favours best plant growth |
Most plants thrive best in neutral pH. Slight acidity favours tree growth and forms forests. Slight alkalinity is favourable for grasses and legume crops. |
|
|
|
What is field capacity/water holding capacity of soil? |
It is the maximum amount of water retained by a soil per unit of its dry weight after the gravitational flow has stopped |
|
|
|
What is gravitational flow |
The water that percolates through a soil due to gravitational force is called gravitational flow |
|
|
|
What determines the water holding capacity of a soil |
The type of soil particles present in the soil and soil porosity |
|
|
|
Name the soil which has very Low water holding capacity |
Sandy soil |
|
|
|
Which soil has the maximum water holding capacity |
Clay soil |
|
|
|
What are enzymes |
Enzymes are biocatalysts, involving in various metabolic reactions in a living system |
|
|
|
How are enzymes different from hormones |
1) all enzymes are protein in nature while hormones can be either proteins, carbohydrates or lipids 2) hormones always have a target organ while enzymes don’t |
|
|
|
What are conjugated enzymes |
The enzymes which have a non protein part along with protein are called conjugated proteins |
|
|
|
What is achromic point |
It is the time taken for salivary amylase to digest starch completely |
|
|
|
How will you confirm the digestion of starch |
On heating with Benedict’s solution it will turn orange |
|
|
|
What is optimum temperature of an enzyme |
It is the temp at which the enzyme shows maximum activity and efficiency |
|
|
|
What is denaturation |
It is the loss of three dimensional structure of a protein or enzyme |
|
