Bio topic 3 (booklet)

Vocabulary-style flashcards covering cell division (mitosis/meiosis), genetics, DNA structure, stem cells, and genetic modification based on the lecture notes.

Nucleus

The part of the cell where chromosomes (DNA) are located and genetic information is stored.

Chromosomes

Strands of DNA found in the nucleus; in humans, there are 23 pairs (46 total) arranged by size and shape.

Gene

A section of DNA that determines the sequence of amino acids to make proteins; they are arranged in a row along a chromosome.

Sex Chromosomes

The 23 pair of chromosomes in humans; males are XY and females are XX

Mitosis

Cell division that produces 2 genetically identical cells with the same number of chromosomes as the original cell, used for growth and repair.

Meiosis

Cell division that produces 4 genetically different gametes (sperm or eggs) containing half the normal number of chromosomes.

Cancer

A result of uncontrolled mitosis where cells divide without control.

Tumour

A group of cells growing out of control that damages the tissues and organs in which they form.

Stem Cells

Unspecialised cells which have the ability to develop into other cells and differentiate into specialised types like muscle, skin, or liver cells.

Meristems

Growing points in the tips of plant shoots and roots that serve as a source of stem cells.

Adult Stem Cells

Stem cells sourced from tissues such as bone marrow, umbilical cords, or babies' teeth.

Embryonic Stem Cells

Stem cells obtained from embryos left over from in vitro fertility (IVF) treatment.

DNA Structure

Two long chains of alternating sugar and phosphate molecules connected by bases, twisted to form a double helix.

DNA Bases

Four molecules—Adenine (A), Thymine (T) Cytosine (C), and Guanine (G)—that follow complementary base pairing (A with T, and C with G).

Triplet Code

A sequence of every 3 bases in DNA that determines the order in which amino acids are linked to form proteins.

Genetic Profiling

The analysis of an organism's DNA by cutting it into short pieces and separating them into bands for comparison.

Gamete

The scientific name for a sex cell (sperm or egg) which contains half the number of chromosomes (23 in humans) of a normal cell.

Zygote

A fertilised egg produced when an egg and sperm join together during fertilisation.

Genetics

The study of heredity; it examines how genes decide characteristics of the body.

Alleles

Two forms of the same gene, represented by letters (e.g., R or r).

Genotype

The genetic make-up of an individual, represented as a pair of alleles (e.g., TT, Tt, or tt).

Phenotype

The physical characteristic that is expressed or shown because of a genotype.

Dominant Allele

An allele that always "shows" in the phenotype when present, represented with a CAPITAL letter.

Recessive Allele

An allele that will be "hidden" by a dominant allele in a heterozygote, represented with a small case letter.

Homozygous

A genetic condition where the two alleles for a gene are identical (e.g., RR or rr).

Heterozygous

A genetic condition where the two alleles for a gene are different (e.g., Rr).

Punnett Square

A diagram used to explain or predict the outcomes of genetic crosses.

Genetically Modified (GM) Crops

Plants produced by transferring genes artificially from one species to another, such as herbicide-resistant soya beans.

Herbicides

Chemicals used by farmers to kill weeds that compete with crops for space and nutrients.