module 4 - producing new cells Flashcards
what is mitosis?
it is the process of a diploid cell dividing, and is controlled by the nucleus
what is a chromatid?
one of the 2 complete copies of a chromosome attached to each other during mitosis
what is a stem cell?
-unspecialised cells in animals which can divide in order to self-renew.
-they have the potential to become different types of cell.
-they are involved in growth and repair
what is a system?
a group of organs which work together
what does the specialisation of cells lead to?
it leads to the formation of a variety of cells, tissues, and organs
what is a diploid?
it is two sets of matching chromosomes in one cell
what is a heirarchy?
it is the order of the different levels of complexity from cells to systems
what is a chromosome complement?
it is the number of chromosomes typical of a particular species
how many chromosomes are there in the human body?
46 and these are arranged into 23 pairs
what do all body cells contain?
they all contain 2 sets of matching chromosomes- one set from the mother and one set from the father.
why are certain cells called diploids?
because they have 2 sets of matching chromosomes
what is the number of chromosomes a diploid cell contains called?
its diploid chromosome complement, each species will have its own chromosome complement
what is the chromosome complement of a human cell?
46
what is a chromosome made of?
two chromatids joined at the centromere
what does DNA replication make?
it makes a copy of each chromosome before mitosis and cell division
what is it called when 2 chromatids join together?
A chromosome
what is the combination of 2 joined chromatids called?
it is still called one chromosome
why do cells need to divide?
-when unicellular organisms divide, they form a complete copy of themselves
-multicellular organisms divide to produce new cells for growth, and repair of damaged tissues and replacement of dead and damaged cells
what happens during mitosis?
two identical daughter cells are produced which contain the same number of chromosomes as the parent cell
why is what happens during mitosis important?
so that they maintain the diploid chromosome complement and so that the cell can carry out the same functions as the parent cell
what is stage 2 of mitosis?
chromosomes make copies of themselves and become visible as pairs of identical chromatids
what is stage 3 of mitosis?
chromosomes line up at the equator of the cell
what is stage 4 of mitosis?
spindle fibres attach to chromosomes and chromatids are pulled apart
what is stage 5 of mitosis?
chromatids move to opposite poles
what is stage 6 of mitosis?
nuclear membrane forms and cytoplasm divides
what does the nucleus contain during mitosis?
long uncoiled chromosomes which are difficult to see
how do stem cells self renew?
by cell division
what are the types of stem cells?
-embryonic stem cells
-tissue stem cells
what are embryonic stem cells derived from?
embryos that develop from eggs that have been fertilised in a laboratory
what do stem cells reside among?
differentiated cells in a tissue or organ, they are found in many tissues such as bone marrow, brain, skeletal muscle, blood vessels, skin, liver, teeth, and the heart
what do stem cells do?
regenerate surrounding cells damaged by disease, injury, and every day wear and tear
what is a nerve cells structure and function?
long connection length for transmitting signals over long distances from sensors to the brain
what is are red blood cells structure and function?
they have a biconcave shape and no nucleus giving them a large surface area so it can carry more oxygen
what is a sperm cells structure and function?
has a tail to swim to the egg and fertilise it
what is a root hair cells structure and function?
long and thin so it has a large surface area to absorb more water
what is a leaf palisade cells structure and function?
has many chloroplasts to carry out photosynthesis
what are tissues made up of?
many copies of a specialised cell type
what combines to make an organ?
different tissue types
what do organs work together to form?
a system
What is stage 1 of mitosis?
Nucleus contains long uncoiled chromosomes which are difficult to see
What are some substances that move by diffusion?
-oxygen
-nutrients
-waste products
What are some substances that move by active transport?
-sugars
-most amino acids
