Heredity And Evolution

Question 1

What is heredity?

Answer 1

The process of passing traits or characters from parents to offspring.

Question 2

The offspring of parents is also called ________.

Answer 2

progeny

Question 3

Explain the 2 types of traits.

Answer 3

[A] Inherited traits

1. They are the traits that are transferred from parents to offspring.
2. eg; height, skin, color, hair, etc.
3. These are present in genes.
4. These are genetic variations caused in the DNA inside the nucleus

[B] Acquired traits

1. Traits that are developed throughout the lifetime of the individual.
2. eg; learning skills
3. These are somatic variations which are caused outside the nucleus.

Question 4

The opposite of genetic is ___________ .

Answer 4

Somatic

Question 5

__________ is also called the father of inheritance.

Answer 5

Gregor Mendel

Question 6

How Gregor Mendel found out the rules for inheritance?

Answer 6

He studied the lifespan of pea plant (also called Pisum Sativum) to find out the rules of inheritance. He choose pea plant because -

1. It was easy to grow.
2. It had short life cycle (around 3 months) and therefore, it was easy to study a large number of generations of that.
3. Pea plants are bisexual too.
4. It has 7 pairs of contrasting characters.

Question 7

What is dominant trait?

Answer 7

The trait which expresses itself both in the presence and absence of the recessive trait.

Question 8

What is recessive trait?

Answer 8

The trait which expresses itself only in the absence of dominant trait.

Question 9

What is Allele?

Answer 9

Different forms of a given gene are called alleles.
eg, T-allele is responsible for tallness.
t-allele is responsible for dwarfness.

Question 10

What is phenotype?

Answer 10

It refers to observable physical appearance of a given organism.
eg; tall plant, round seeds, etc.

Question 11

What is genotype?

Answer 11

It refers to the genetic code responsible for any given phenotype.
eg; (TT) - is responsible for tallness
(tt) - is responsible for dwarfness

Question 12

What is the difference between Homozygous and Heterozygous?

Answer 12

Homozygous refers to the condition when same type of allele is present for a given phenotype. eg; tt, TT.
Heterozygous refers to the condition when different type of allele is present for a given phenotype. eg; Tt

Question 13

The study of single trait is called _________ .

Answer 13

Monohybrid Cross

Question 14

The study of single trait is called _________ .

Answer 14

Monohybrid Cross

Question 15

The children of parental generation is called _________, while the child of the children of parent generation is called _____________.

Answer 15

First filial generation (F1)

Second filial generation (F2)

Question 16

The ratio of all possible genotypes is called ___________ .

Answer 16

genotypic code

Question 17

The ratio of all possible phenotypes is called ____________.

Answer 17

Phenotypic ratio

Question 18

The possibilities of offspring can be represented through ___________.

Answer 18

Punnett Square

Question 19

Describe Mendel’s Principles.

Answer 19

1. Law of Dominance - some alleles are dominant and cover up the recessive alleles.
2. Law of Segregation - The allele that exist in pairs that separate during gamete formation. which means for a Tt organism, some of its gametes will have T allele and some will have t allele. So, depending upon which male gamete fertises which female gamete, the new zygote will possess that traits.
3. Law of Independent Assortment - The alleles of different genes are inherited independently within the organisms which reproduce sexually.
   which means that the 2 genes transferred are not in packets so one allele has nothing to do with the other

Question 20

Describe Sex determination in Humans.

Answer 20

In human body, each cell has 46 chromosomes, these chromosomes are 23 in pair. In males, the one pair is a pair of X chromosome and Y chromosome. In females, the one pair is a pair of X chromosome and X chromosome. These X and Y chromosome are called sex chromosomes.
When male gamete fuses with the female gamete, then if the male gamete contained X chromosome which when fuses with the female’s X chromosome, then the result is a female, but if the male gamete contained Y chromosome, then the result is a male.

Question 21

Chromosomes in humans other than sex chromosomes are called _____________ .

Answer 21

Autosomes

Question 22

How traits get expressed?

Answer 22

Cellular DNA is the information source for making proteins. A section of DNA that provides information for one protein is called the gene for that protein.
According to the genotypes, the proteins will manufacture some particular enzymes which will make that particular hormone which will trigger to express a particular trait.
According to genotypes, more, less for medium efficient hormones will be made which will trigger to express a particular trait.

Question 23

__________ produces enzymes in our body.

Answer 23

Amino acids

Question 24

State true or false:

does every cell of the body has the same DNA?

Answer 24

True