Quick Review Flashcards - Click to flip and test your knowledge!
Question
What is the scientific term for the study of heredity and the laws relating to the transmission of body features from parents to offspring?
Answer
Genetics
Question
Who is known as the 'Father of Genetics'?
Answer
Gregor J. Mendel
Question
The technique of altering the genetic constitution of an organism by introducing new genes into its chromosomes is called _____.
Answer
Genetic engineering
Question
What was the first hormone produced through genetic engineering by introducing mammalian genes into bacteria?
Answer
Insulin
Question
Which practice involves advising newly married couples on the possibility of their children inheriting undesirable genetic traits?
Answer
Genetic counselling
Question
List three examples of genetic diseases mentioned in the text that can be identified through genetic matching of parents.
Answer
Haemophilia, thalassaemia, and sickle cell anaemia.
Question
Term: Heredity
Answer
Definition: The transmission of genetically based characteristics from parents to offspring.
Question
What phrase is used in biology to describe the observation that young ones typically look like their parents?
Answer
Like begets like
Question
The small differences found among individuals of the same species are known as _____.
Answer
Variations
Question
Concept: Character
Answer
Definition: Any inheritable feature of an organism (e.g., eye colour).
Question
Concept: Trait
Answer
Definition: The alternative forms of a character (e.g., blue eyes or brown eyes).
Question
In humans, is the 'rolling of tongue' considered a dominant or recessive trait?
Answer
Dominant
Question
Which human blood group trait is dominant: $Rh$ positive or $Rh$ negative?
Answer
$Rh$ positive
Question
What are the two alternative traits for the character 'Hair shape' in humans?
Answer
Curly hair and straight hair.
Question
What is the name for the artificial arrangement of chromosomes according to their size and shape on a chart?
Answer
Karyotype
Question
How many total chromosomes are found in each body cell of a human?
Answer
$46$
Question
How many pairs of chromosomes are present in a human cell?
Answer
$23$ pairs
Question
A pair of corresponding chromosomes of the same shape and size, with one obtained from each parent, is called _____.
Answer
Homologous chromosomes
Question
What term refers to the first $22$ pairs of chromosomes in humans that determine general body features?
Answer
Autosomes
Question
The $23^{rd}$ pair of chromosomes in humans, which determines the gender of the individual, is called _____.
Answer
Sex chromosomes (or allosomes)
Question
Which sex chromosome combination results in a human female?
Answer
$XX$
Question
Which sex chromosome combination results in a human male?
Answer
$XY$
Question
In humans, the sex of the child is determined by the kind of _____ that fertilises the egg.
Answer
Sperm
Question
What percentage of human sperms carry a $Y$ chromosome?
Answer
$50$ percent
Question
Specific segments of DNA on a chromosome that determine hereditary characteristics are called _____.
Answer
Genes
Question
Which human chromosome contains the largest number of genes ($2968$)?
Answer
Chromosome No. 1
Question
Term: Genome
Answer
Definition: The full complement of DNA, including all genes and intergenic regions, of an organism.
Question
Who coined the term 'gene' in 1909?
Answer
Wilhelm Johannsen
Question
What is the name of the simple diagram used to predict the possible combinations of offspring genotypes?
Answer
Punnett square
Question
What is the scientific name for the garden pea used by Mendel for his experiments?
Answer
$Pisum\ sativum$
Question
Why did Mendel choose the garden pea because of its pollination method?
Answer
Peas are normally self-pollinated but can be cross-pollinated artificially.
Question
A cross involving only one feature at a time, such as plant height, is a _____ cross.
Answer
Monohybrid
Question
A cross involving two pairs of contrasting characters is known as a _____ cross.
Answer
Dihybrid
Question
In Mendel's experiments, what does '$F_{1}$' stand for?
Answer
First Filial generation
Question
What is the phenotypic ratio of a monohybrid cross in the $F_{2}$ generation?
Answer
$3:1$
Question
What is the genotypic ratio of a monohybrid cross in the $F_{2}$ generation?
Answer
$1:2:1$
Question
What is the phenotypic ratio of a dihybrid cross in the $F_{2}$ generation?
Answer
$9:3:3:1$
Question
Which of Mendel's laws states that in a heterozygous pair, only the dominant character expresses itself?
Answer
Law of Dominance
Question
Which law states that the two members of a pair of factors separate during the formation of gametes?
Answer
Law of Segregation (or Law of Purity of Gametes)
Question
Which law states that the distribution of alleles of one character into gametes is independent of the distribution of alleles of another character?
Answer
Law of Independent Assortment
Question
An alternative form of a gene occupying the same position on homologous chromosomes is called an _____.
Answer
Allele
Question
What term describes an individual having identical alleles for a particular character (e.g., $RR$ or $rr$)?
Answer
Homozygous
Question
What term describes an individual having contrasting alleles for a particular character (e.g., $Rr$)?
Answer
Heterozygous
Question
The observable characteristic or physical expression of an organism's genes is called its _____.
Answer
Phenotype
Question
The genetic makeup or set of genes present in an organism is called its _____.
Answer
Genotype
Question
Under what condition can a recessive character express itself phenotype-wise?
Answer
Only when the pair consists of both recessives (homozygous recessive).
Question
Sex-linked inheritance usually refers to the appearance of traits due to alleles exclusively on the _____ chromosome.
Answer
$X$
Question
Why is colour blindness more common in males than females?
Answer
Males have only one $X$ chromosome, so a single recessive gene will cause the disorder.
Question
What is the common name for haemophilia, characterized by the failure of blood to clot?
Answer
Bleeder's disease
Question
What term is used to describe the inheritance of $X$-linked genes where the mother passes the trait to the son and the father passes it to the daughter?
Answer
Criss-cross inheritance
Question
Term: Mutation
Answer
Definition: A sudden change in one or more genes, or in the number or structure of chromosomes.
Question
Which blood disease is caused by a gene mutation that results in the production of sickle-shaped RBCs?
Answer
Sickle cell anaemia
Question
What environmental factor is mentioned as a cause for altering gene structure, as seen in Japan after World War II?
Answer
Radioactive radiations
Question
In a $F_{2}$ generation of Mendel's pea height cross, what is the phenotype of an individual with the genotype $Tt$?
Answer
Tall
Question
Is the trait of 'free ear lobes' dominant or recessive in humans?
Answer
Dominant
Question
Is 'red-green colour blindness' a dominant or recessive trait?
Answer
Recessive
Question
What is the recessive trait corresponding to 'right-handedness' in humans?
Answer
Left-handedness
Question
Regarding seed shape in peas, which trait is dominant: round or wrinkled?
Answer
Round
Question
Regarding pod colour in peas, which trait is recessive: green or yellow?
Answer
Yellow
Question
What is the difference between a 'monohybrid' and 'dihybrid' cross?
Answer
A monohybrid cross studies one character, while a dihybrid cross studies two pairs of contrasting characters simultaneously.