Biology - first rotation

Female reproductive system

A series of glands, tissues, organs involved in producing offspring, It also makes and releases eggs and hormones.

function of female reproductive system

produces hormones like estrogen and progesterone, supports fertilization and fetal development during pregnancy, and enables childbirth through the uterus and cervix

Male reproductive system

A series of glands, tissues and organs involved in producing offspring. It makes sperm and delivers it to the female reproductive system. It also produces hormones.

Function of Male reproductive system

produces sperm and the hormone testosterone, which is essential for male sexual development and fertility. It also delivers sperm to the female reproductive system during intercourse to enable fertilization.

Uterus

An organ in the female reproductive system where a foetus is nourished and protected

Ovary

One of a pair of female glands which produce ova/eggs and where the hormones estrogen and progestrone are made.

Fallopian tube

A tube in the female reproductive system connecting the uterus and the ovary. It is where the egg and sperm meet and how a zygote makes it to the uterus.

Cervix

A muscular organ at the base if the uterus which connects it to the vagina. It allows fluids to pass between the two.

Vagina

Stretchy, muscular canal into which sperm is released and allows humans to give birth

Bladder

a hollow muscular organ used for storing urine

Testes

2 small organs found inside the scrotum. They create sperm and produce the hormones testosterone and oestrogen.

Scrotum

The bag of skin that protects the testes. They also keep them cool.

Epididymus

A narrow tightl coiled tube that is attached to each testicle. Sperm cells move here to fully mature

Vans deferens

A tube that carries sperm out to the testes to the prostate gland.

Prostate gland

A small organ that secrets fluids to norish the sperm.

Seminal vesticular

two glands that produce fluids which are used by the prostate glands

Penis

An organ that releases sperm into the vagina

Urethra

A tube where sperm and urine leave the penis

Interphase

A period of growth, development and DNA replication in the cell cycle. It is split into stages G1, S1 and G2

G1 (gap 1)

The first growth stage in interphase where the DNA in the nucleus is replicated

S1 (synthesis 1)

A stage in interphase where the DNA is replicated

G2 (Gap 2)

A second period of growth in a cell where the cell finishes growing. After, mitosis begins.

Mitosis

The process where the cells chromosones segregate producing 2 new nuclei in preperation for cell division

Why mitosis happens

Cells need to divide so living things can grow, repair damaged tissues, and maintain efficient nutrient and waste exchange, which becomes difficult if a cell grows too large.

Prophase

First stage of mitosis, the DNA condenses into chromosomes

Prometa phase

second stage of mitosis where microtubials (protein strands) appear from the centrozones and nucleus membrane disappears. Microbial strands continue to grow, attaching to protein structures on the chromosones.

Metaphase

Third stage of mitosis, the chromosones align along the centre of the cell (in single file) so that they face opposite sides of the cell

Anaphase

Fourth stage of mitosis, the microtubular strands shorten, pulling the chromosomes away from each other

Telophase

Final stage of mitosis, the microtubial strands break up and pull away. A new nuclos forms around each set of chromosomes as hey unravel.

Cytokines

A contractile ring divides the cell and the organelles/cytoplasm are replicated.

Cell cycle

A cell cycle is a series of events that takes place in a cell as it grows and divides.

Meiosis

A type of cell division that reduces the number of chromosones in the parent cell by half to produce 4 gamete cells

Why meosis happens

Meiosis happens to produce sex cells (sperm and eggs) with half the number of chromosomes, ensuring genetic variation and maintaining the correct chromosome number in offspring.

Prophase 1

DNA condenses and lines up with their homologous pair. The DNA also crosses over (they swap genes and geneitic information)

Pro-metaphase 1

second stage of mitosis where microtubials (protein strands) appear from the centrozones and nucleus membrane disappears. Microbial strands continue to grow, attaching to protein structures on the chromosones.

Metaphase 1

Third stage of mitosis, the chromosones align along the centre of the cell (in their pairs) so that they face opposite sides of the cell.

Anaphase 1

Fourth stage of mitosis, the microtubal strands shorten, pulling the chromosomes pairs away from each other

Telophase 1

, the microtubial strands break up and pull away. A new nuclos forms around each half of the chromosomes

PMAT 2

This cycle in repeated (except for crossing over), and the chromosones are pulled apart like in mitosis.

DNA

a chemical structure found in all living things that stores information about an organism. It lives in the nucleus, controlling how an organism develops, how body parts are assembled and how they work together. It does this by providing instructions on how amino acids join together to make proteins.

Structure of DNA

DNA is a double helix composed of two strands. Each strand consists of nucleotides made up of a phosphate group, deoxyribose sugar, and one of four nitrogenous bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The strands are held together by hydrogen bonds, with A pairing with T and C pairing with G.

Chromosones

complex molecules found in the nucleus of cells. They are made of DNA (deoxyribonucleic acid).

Double helix

twisted shape of DNA

Nucleotide

Sub units of DNA made of a base, deoxyribose sugar and a phosphate group (P04)

Genes

specific sequences of nucleotides that code for a specific protein. The length and sequence of a gene determines the size and shape of the protein, thus its function.

RNA

Sections of ½ copied DNA that escape the nucleus. It goes the the ribosomes (protein makers of the cell) to tell them what to do.

How DNA replicates

DNA replication is the process by which DNA makes an exact copy of itself. Helicase unwinds the DNA double helix and separates the two strands. Primase adds RNA primers, which are needed for DNA polymerase to begin adding new nucleotides. DNA polymerase adds complementary nucleotides in the 5' to 3' direction. On the leading strand, replication occurs continuously, while on the lagging strand, it happens in small segments called Okazaki fragments. After replication, RNA primers are replaced with DNA, and the fragments on the lagging strand are joined by ligase. The result is two identical DNA molecules, each containing one old (parent) strand and one new (daughter) strand.

Complimentary base

The specific pairing of bases in DNA (A pairs with T, C pairs with G).

How cells know what proteins to make

The sequence of nitrogenous bases (A, T, C, G) in DNA forms a genetic code. Codons, which are groups of three bases, specify an amino acid. During transcription, the DNA sequence is copied into mRNA, which then exits the nucleus. The mRNA travels to the ribosomes, where translation occurs. During translation, the mRNA is used to assemble amino acids into a protein at the ribosome.

Inheritance

The process by which genetic information is passed from parents to offspring.

Allele

different versions of a gene. You inherit 1 from your mother and another from your father

Heterozygous

2 different alleles in 1 organism

Homozygous

2 of the same allele in 1 organism

Dominant allele

Allele will always be expressed no matter what

Recessive allele

Only expressed where there are 2 allele

Genotype

Collection of all the alleles we have

Phenotype

Characteristics we get from our genotype

Diploid

a cell or organism with two complete sets of chromosomes

Haploid

A term to describe a cell or organism with a single set of unpaired chromosomes