Biology Flashcards
What are the ovaries and what is their function?
- Paired organs located on either side of the uterus
- Produce eggs (ova) and hormones e.g. oestrogen and progesterone,
What are the fallopian tubes and what is their function?
- Tubes connecting the ovaries to the uterus.
- Fertilisation typically occurs here when sperm meets an egg.
What is the uterus and what is its function?
- Pear Shaped Organ
- It houses the developing foetus during pregnancy and contracts during labour to expel the baby
What is the cervix and what is its function?
-Entrance to the uterus
-Gains a plug when child is in womb
What is the vagina and what is its function?
- It receives the penis during sexual intercourse
- Serves as the passage for menstrual blood and acts as the birth canal.
-A muscular canal that extends from the vulva to the neck of the uterus (cervix).
What are the testes and what is their function?
- Paired organs located in the scrotum
- Produce sperm through spermatogenesis
- Secrete testosterone
What is the scrotum and what is its function?
- Pouch of skin and muscle housing the testes
- Maintains the temperature of the testes slightly lower than body temperature
What is the epididymis and what is its function?
- Coiled tubes located behind each testicle
- Store and mature sperm
- Transport sperm from the testes to the vas deferens during ejaculation
What are the seminal vesicles and what is their function?
- Glands located near the base of the bladder
- Produce seminal fluid, a component of semen that provides energy and protection for sperm
What are the two types of chromosomes and what are they?
The two types of chromosomes are autosomes (somatic cells) and sex chromosomes (gender-determining)
What is the prostate gland what is its function?
- A gland located beneath the bladder and surrounding the urethra
- Produces prostatic fluid, which mixes with sperm and seminal fluid to form semen
- Helps neutralise acidic vaginal pH.
What is the urethra (male) and what is its function?
- The tube that carries semen and urine from the bladder out of the body
- Serves as the passage for both urine and semen, allowing for ejaculation and sexual intercourse
What is the centromere?
The region of a chromosome where the sister chromatids are held together and where the spindle fibres attach during mitosis is called the centromere
What is a chromatid?
A chromatid is one identical half of a chromosome
What is chromatin?
Chromatin is a complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells.
What are autosomes?
Autosomes are the chromosomes in the body that determine the characteristics of an organism.
What is the penis and what is its function?
- The external male genital organ
- Enables sexual intercourse and ejaculation
- Contains erectile tissue that becomes engorged with blood during arousal
What are sex chromosomes?
Sex chromosomes are involved in gender determination. There are two, in the forms of X and Y. Males have XY. Females have XX.
What is a chromosome?
Chromosomes are thread-like structures made of DNA and wrapped in a protein, referred to as, ‘Histone’ found in the nucleus of eukaryotic cells. They carry genetic information in the form of genes, which are units of heredity responsible for specific traits.
What is a karyotype?
A karyotype is an individual’s complete set of chromosomes.
What is mitosis?
Mitosis is a type of cell division in eukaryotic, somatic cells, resulting in two genetically identical daughter cells from a single parent cell. Mitosis serves as an essential factor of somatic cell reparation, general growth and of asexual reproduction.
What is the structure of DNA?
- DNA consists of two long strands forming a twisted ladder, referred to as a double helix.
- Each strand is made of repeating units called nucleotides, each comprising:
- A phosphate group
- A five-carbon sugar (deoxyribose)
- A nitrogenous base (Adenine, Thymine, Cytosine, or Guanine)
- Backbone: The sugar-phosphate backbone is on the outside, with the bases on the inside.
- The two strands run antiparalled to each other
- The double helix has major and minor grooves, which are important for protein binding.
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What happens in interphase?
- Cell grows in size to accommodate additional chromosomes,
- DNA replication occurs, leading to there being 92 chromosomes in the nucleus,
- Extra organelles and proteins are created for the daughter cells
What happens in prophase?
- Chromatin condenses into visible chromosomes, each consisting of two sister chromatids joined at the centromere.
- The spindle, made of microtubules, begins to form from the centrosomes.
What happens in metaphase?
- Chromosomes align along the centre of the cell. This alignment ensures that each daughter cell will receive one copy of each chromosome.
What happens in anaphase?
- Sister chromatids are pulled apart by the spindle fibres towards opposite poles of the cell. This separation ensures that each pole will have an identical set of chromosomes.
What happens in telophase?
- Chromatids arrive at opposite poles and begin to decondense back into chromatin.
- The nuclear envelope re-forms around each set of chromosomes, creating two separate nuclei.
How does DNA code for proteins?
- The sequence of bases encodes genetic instructions, essential for the development and functioning of living organisms and many viruses
What is the base pairing of the complementary nitrogenous bases?
- Base Pairing:
- Adenine (A) pairs with Thymine (T) through two hydrogen bonds.
- Cytosine (C) pairs with Guanine (G) through three hydrogen bonds.
What is the function of DNA?
- DNA stores genetic information vital for the growth, development, functioning, and reproduction of all living organisms.
What is a kinetochore?
A region on a chromosome associated with cell division
What is a telomere?
A cap of DNA on the tip of a chromosome that enables DNA to be replicated safely without losing valuable information
What is Cytokinesis?
- Cytokinesis is the final step of cell division, where the cytoplasm divides, forming two distinct daughter cells.
How does the process of cytokinesis differ between plant and animal cells?
- In animal cells: A contractile ring forms a cleavage furrow that pinches the cell membrane inwards until the cell is split into two.
- In plant cells: A cell plate forms along the centerline, developing into a separating wall.
What is the enzyme that unzips the gene and creates m-Rna?
The Rna Polymerase
When the Rna polymerase begins to read the nucleotides and creates corresponding nitrogenous bases for the m-Rna, what is this process called?
The process is called Transcription
Where does the m-Rna travel to after being fully processed by the Rna polymerase?
It travels outside of the nucleus, into the cytoplasm
What does the m-Rna do inside of the cytoplasm?
The M-Rna is read by the protein factories inside of the cytoplasm called ribosomes where amino acid chains are created
What is an amino acid chain called?
A polypeptide
What is the function of t-Rna molecules?
When the ribosome reads the m-Rna in triplets, the t-Rna molecules delivers the corresponding amino acid creating a long chain called a polypeptide.
What is a t-rna molecule?
-A molecule that contains 3 bases ( Adenine, Uracil, Guanine, Cytosine) that code for 1 specific amino acid
- Applied to for the corresponding bases of the m-Rna chain
When does the Ribosome know when the polypeptide is complete?
It will run into a “stop” codon sequence that dictates the polypeptide is done, forming a full protein
