Question on heredity

Question 1

Accumulation of radiation during reproduction

Answer 1

• when organisms reproduce, the offspring, so show some variations due to inaccuracies Indiana, copying. This variations, unless in a sexual reproduction, and more in sexual reproduction.
• Some variations are useful variations, and they help the organism to adjust to the surroundings in the environment. Some variations do not help in the organism to adjust to changes in the environment, and they may die and become extant.
• Bacteria that can withstand heat will survive, better in a heat wave

Question 2

Accumulation of radiation during reproduction

Answer 2

• when organisms reproduce, the offspring, so show some variations due to inaccuracies Indiana, copying. This variations, unless in a sexual reproduction, and more in sexual reproduction.
• Some variations are useful variations, and they help the organism to adjust to the surroundings in the environment. Some variations do not help in the organism to adjust to changes in the environment, and they may die and become extant.
• Bacteria that can withstand heat will survive, better in a heat wave

Question 3

What is DNA copying? State it’s importance.

Answer 3

A process where DNA molecule produces two similar copies of itself in a reproducing cells is called a DNA copying.
It’s important:-
- It makes the transmission of characters from parent to the next generation possible
- It causes variation in a population.

Question 4

Rules for inheritance of character

Answer 4

• characters are transferred through genes present in the DNA molecule in the chromosomes are present in the nucleus of the cell
• The inheritance of characters is due to the fact that both the father and the mother contributes equal amount of genetic material to the child, so, for each trait is governed by a gene, which intern is represented by two factors or alleles one allele from the father, and one allele from the mother.

Question 5

The tendency of an offspring to resemble it’s parent is known as

Answer 5

Heredity

Question 6

Why did Mendel choose the plans for this experiment?

Answer 6

• be is a one year plan. Its lifecycle is very short. So, unless times study of many generations can be carried out.
• male and female reproductive organs are on one flower means flowers are bisexual
• It is easy to do cross-pollination, artificially
• The pea plant has seven characteristics influenced by both the dominant and recessive alleles

Question 7

medal’s contributions

Answer 7

• known as father of genetics
  austrian monk
• studied the inheritence of traits in pea plants
• developed the laws of inheritence
• mendel’s work was not recognized until the turn of the 20th century

Question 8

Describe the mechanism of inheritance

Answer 8

• If both parents help to determine the trait in the progeny, both parents must be contributing a copy of the same gene.
• Thus, each pea plant must have two sets of all genes, one inherited from each parent. So, each germ cell must have only one gene set.
• Each set of gene is present not as a single thread of DNA, but as separate independent pieces called chromosome.
  Each cell of the body will have two copies of each chromosome, one inherited from each parent, i.e. one from male parent and one from female parent.
• When two germ cells combine, they will restore the normal number of chromosomes in the progeny. This ensures the stability of the DNA of species. Such mechanism of inheritance explains the result of Mendel’s experiments. It is used by all sexually and asexually reproducing organisms.

Question 9

Define sex determination

Answer 9

The process by which is sex of a new born individual is it in mind is called sex determination

Question 10

Describe sex determination

Answer 10

• There are different strategies by which sex is determined in different species. In some species, environmental factors are important in determining the sex of. the developing individual.
• For example, in reptiles the temperature at which the fertilised eggs are kept, determines the sex of the offspring. In other animals, such as snails, individuals can change sex in different conditions, indicating that sex is not genetically determined.)
• In human beings, there are 23 pairs of chromosomes, out of which 22 pairs are autosomes and one pair is sex chromosome. These sex chromosomes vary in males and females. A male has one X and one Y-chromosome, i.e. half male gametes or sperms will have short Y-chromosome and other half will have X-chromosome. A female has two X-chromosomes, i.e. all the female gametes (ova) will have only X-chromosome.
• All children obtain either chromosome from both parents.
  Females have a perfect pair of sex chromosome (homogametic) and thus, contribute X-chromosome to both the sexes of progeny but males have a mismatched pair (heterogametic) in which one is X (normal sized) and the other is Y-chromosome (short in size).
• Hence, an egg fertilised by X carrying sperm results in a zygote with XX, which becomes a female and if an egg is fertilised by Y carrying sperm, it results in a XY zygote that becomes male. Thus, the sex of the children will be determined by what they inherit from their father. A child who inherits an X-chromosome will be a girl and one who inherits a Y-chromosome will be a boy.