Samacheer Kalvi solutions for Science [English] Class 10 SSLC TN Board chapter 18 - Genetics [Latest edition]

According to Mendel alleles have the following character ______.

9 : 3 : 3 : 1 ratio is due to ______

The region of the chromosome where the spindle fibres get attached during cell division ______

The centromere is found at the centre of the ______ chromosome.

The ______ units form the backbone of the DNA.

Okasaki fragments are joined together by ______.

The number of chromosomes found in human beings is ______.

The loss of one or more chromosomes in ploidy is called ______.

The pairs of contrasting character (traits) of Mendel are called ______.

The physical expression of a gene is called ______.

The thin thread-like structures found in the nucleus of each cell are called ______.

DNA consists of two ______ chains.

An inheritable change in the amount or the structure of a gene or a chromosome is called ______.

A typical Mendelian dihybrid ratio of F₂ generation is 3:1.

A recessive factor is altered by the presence of a dominant factor.

Each gamete has only one allele of a gene.

Hybrid is an offspring from a cross between genetically different parents.

Some of the chromosomes have an elongated knob-like appendages known as telomere.

New nucleotides are added and a new complementary strand of DNA is formed with the help of enzyme DNA polymerase.

Down’s syndrome is a genetic condition with 45 chromosomes.

Match the following.

What is a cross in which the inheritance of two pairs of contrasting characters are studied?

Name the conditions when both the alleles are identical?

A garden pea plant produces axial white flowers. Another of the same species produced terminal violet flowers. Identify the dominant trait?

What is the name given to the segments of DNA, which are responsible for the inheritance of a particular character?

Name the bond which binds the nucleotides in a DNA.

Why did Mendel select pea plants for his experiment?

What do you understand by the terms phenotype and genotype?

What are allosomes?

What are Okazaki fragments?

Why is euploidy considered to be advantageous to both plants and animals?

A pure tall plant (TT) is crossed with the pure dwarf plant (tt), what would be the F₁ and F₂ generations? Explain.

Explain the structure of a chromosome.

Label the parts of the DNA in the diagram given below. Explain the structure briefly.

Explain with an example the inheritance of the dihybrid cross. How is it different from monohybrid cross?

How is the structure of DNA organized?

What is the biological significance of DNA?

The sex of the newborn child is a matter of chance and neither of the parents may be considered responsible for it. What would be the possible fusion of gametes to determine the sex of the child?

Flowers of the garden pea are bisexual and self-pollinated. Therefore, it is difficult to perform a hybridization experiment by crossing a particular pistil with the specific pollen grains. How Mendel made it possible in his monohybrid and dihybrid crosses?

Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in the F₁ generation are then selfed to produce F₂ generation of pea plants.

What do the plants of the F₁ generation look like?

Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in the F₁ generation are then selfed to produce F₂ generation of pea plants.

What is the ratio of tall plants to dwarf plants in the F₂ generation?

Pure-bred tall pea plants are first crossed with pure-bred dwarf pea plants. The pea plants obtained in the F₁ generation are then selfed to produce F₂ generation of pea plants.

Which type of plants was missing in the F₁ generation but reappeared in the F₂ generation?

Kavitha gave birth to a female baby. Her family members say that she can give birth to only female babies because of her family history. Is the statement given by her family members true? Justify your answer.

Under which conditions does the law of independent assortment hold good and why?