Inheritance Flashcards
What is the process by which parents pass on their characteristics to their offspring?
Inheritance
Inheritance is a fundamental concept in genetics.
What is the study of inheritance called?
Genetics
Genetics encompasses the study of genes and heredity.
Where are the genes from the father located?
Inside the sperm nucleus
Sperm carry genetic material from the father.
Where are the genes from the mother located?
Inside the egg nucleus
Eggs carry genetic material from the mother.
What forms when the nucleus of the sperm joins with the nucleus of the egg?
A fertilised egg or zygote
This marks the beginning of a new individual’s development.
How many genes do offspring receive from each parent?
Half from the father and half from the mother
This results in a combination of traits from both parents.
What do nearly all cells contain that is crucial for inheritance?
A nucleus
The nucleus houses the genetic material necessary for inheritance.
What are chromosomes?
Thread-like structures that carry genes
Chromosomes are essential for the organization of DNA.
How many chromosomes do humans have?
46
This total is referred to as the diploid number.
What is the diploid number?
The full number of chromosomes in a somatic cell
For humans, this number is 46.
How many pairs of chromosomes do humans have?
23 pairs
Each pair consists of one chromosome from each parent.
True or False: Different species have the same number of chromosomes.
False
Different species have varying numbers of chromosomes.
How many pairs of chromosomes do cats have?
19 pairs
This is an example of variation in chromosome number among species.
How many pairs of chromosomes do fruit flies have?
4 pairs
This illustrates a significant difference in chromosome count compared to humans.
Fill in the blank: A gene is a small section of ______ on a chromosome.
DNA
Genes are the basic units of heredity.
What is a gene?
A gene is a segment of DNA that carries genetic information affecting growth and appearance
Examples include genes for eye color, hair color, and height.
What is DNA?
DNA stands for deoxyribonucleic acid, a long thread-like molecule that makes up chromosomes.
What is the structure of a DNA molecule?
A DNA molecule is a polymer made up of thousands of repeated units called nucleotides.
What are the components of a single nucleotide?
A single nucleotide is made up of three molecules:
* phosphate
* sugar
* base
What forms the backbone of the DNA strand?
The backbone of the DNA strand is formed by the sugar and phosphate molecules.
How is DNA structurally organized?
DNA consists of two strands of nucleotides twisted into a double helix.
What do the sugars and phosphates represent in the DNA structure?
The sugars and phosphates make up the uprights of the ladder-like structure of DNA.
What do the bases form in the DNA structure?
The bases form the rungs of the ladder in the DNA structure.
What is base pairing in DNA?
Base pairing refers to the specific pairs of bases held together by hydrogen bonds.
Which bases pair together in DNA?
The bases pair as follows:
* Adenine (A) pairs with Thymine (T)
* Cytosine (C) pairs with Guanine (G)
What holds the two chains of nucleotides together in DNA?
The two chains are held together by hydrogen bonds between paired bases.
What is the significance of the hydrogen bonds in DNA?
Although weak individually, the many hydrogen bonds collectively maintain the shape of the double helix.
Fill in the blank: A single gene is made of a short length of _______.
DNA
True or False: DNA is a single-stranded molecule.
False
What shape does the DNA molecule resemble?
The DNA molecule resembles a spiral staircase.
What is the role of enzymes in cells?
Enzymes control all the chemical reactions in the cells.
What are all enzymes classified as?
Proteins.
How does DNA influence enzyme production?
DNA codes for proteins, determining which enzymes are produced in each cell.
What determines the sequence of amino acids in a protein?
The coding DNA.
What bases are found in DNA?
A, T, C, and G.
How is each amino acid coded in DNA?
By a sequence of three bases.
How many different amino acids are there?
About 20.
What is the sequence of bases in DNA that codes for proteins called?
The genetic code.
What is the function of messenger RNA (mRNA)?
Carries a copy of the base sequence on DNA out of the nucleus to the ribosomes.
What process does mRNA use to copy DNA?
The ‘rule of base pairing.’
What type of RNA picks up amino acids and carries them to the ribosomes?
Transfer RNA (tRNA).
What happens at the ribosomes during protein synthesis?
Ribosomes assemble amino acids into protein molecules.
How are amino acids joined together in a protein?
By peptide bonds.
What determines the specific order of amino acids in a protein?
The sequence of bases on the mRNA.
What is the significance of the shape of a completed protein?
It determines the protein’s function, such as the active site of an enzyme.
What can cause mutations in proteins?
Changes to the base sequence of coding DNA.
What can changes in non-coding DNA affect?
The formation of mRNA and the switching of genes on and off.
Fill in the blank: The vital role of _______ is to carry the code to the ribosomes.
mRNA
True or False: Only coding DNA affects protein synthesis.
False.
