Key Area 1: Producing New Cells Flashcards
Mitosis
Provides new cells for growth, repair of damaged tissues and replacement of dead or damaged cells. It also maintains the diploid chromosome complement.
Diploid cells have?
Two matching (paired) sets of chromosomes, which are replicated during mitosis.
Chromosome
a thread-like structure in the nucleus of a cell that contains DNA and carries genetic information
Chromatid
one of two identical halves of a duplicated chromosome
Spindle fibres are?
protein structures that help divide genetic material in a cell during cell division
Equator
the plane where the chromosomes align during metaphase
Diploid chromosome
a chromosome in a cell that contains two sets of chromosomes, one from each parent
Complement
the complete set of chromosomes for a species
Unspecialised cells
a cell that has no specific function but can develop into different types of cells
Tissue stem cells
A TSC is an unspecialized cell that can divide and differentiate into specialized cell
Embryonic stem cells
ESCs are pluripotent stem cells that can divide into more stem cells or become any type of cell in the body
Organs
usually a combination of tissues that are coordinated to perform a variety of functions
Systems
Are groups of organs which work together to form systems
Multicellular
an organism that is made up of more than one cell
Hierarchy of organisation
Cells –> Tissues –> Organs –> Systems –> Organism
Stem cells are involved in?
growth and repair
Organ examples
Stomach, leaf
Tissue
is defined as a collection of cells, together that is specialized to perform one or more particular functions.
Specialization of cells leads to the formation of a?
variety of tissues and organs
Stages of mitosis
- Chromosomes are hidden inside the nuclear membrane. A whole nucleus is visible
- The nuclear membrane breaks down and chromosomes become visible. Each chromosome is double stranded (the two strands are identical and are called chromatids) spindle fibres form.
- Spindle fibres attach to the centre of the chromosome and begin to jostle them into a line
- Chromosomes line up at the equator (middle) of the cell
- Spindle fibres pull one strand from each chromosome to each pole (end) of the cell
- When the single stranded chromosomes reach the poles, a nucleus starts to form at each pole these nuclei are genetically identical.
- At the very end of mitosis the cell will divide into 2 cells. Each of these carries exactly the same genes but they may use different genes e.g one may grow to become muscle tissue and another to from a nerve cell
Cell division is controlled by the??
Nucleus
Animal: Tissue, smooth muscle. Cell type?
smooth muscle cell
Smooth muscle cells specialised structural features?
spindle shape (allowing cells to form sheets capable of contraction)
Smooth muscle cell function
movement of food down oesophagus by peristalsis
Blood, red blood cell specialised structural features?
carry oxygen (exp. carries oxygen as oxyhemoglobin, small enough to fit through capillaries.)
Red blood cell function
uptake and transport of oxygen to living cells
Stomach
churning and partial digestion of food
leaf
photosynthesis and gaseous exchange
Root epidermis, root hair cell features?
Long extension of an epidermal cell presenting a large surface area in contact with soil solution
Root hair cell function?
absorption of mineral and water salts
