Do sponges have a heart? In summary, sponges – or poriferans – do not have a true circulatory system as most animals do. There is no heart, there are no veins or arteries, and sponges do not have blood. Water is pulled into the sponge via internal choanocyte cells, which take in water through the […]
How does a Punnett squares allow you to predict gametes and offspring?
How does a Punnett squares allow you to predict gametes and offspring? A Punnett square is a chart that allows you to easily determine the expected percentage of different genotypes in the offspring of two parents. The gametes produced by the male parent are at the top of the chart, and the gametes produced by […]
What is light quality?
What is light quality? Light quality is the wavelength (in nanometers, nm) within the electromagnetic spectrum; i.e. blue light is 450 nm and red light is 650 nm. Each wavelength has a different packet of radiation or energy (in J mol-1) called photons. What type of light causes damage to plants? UV-B radiation has been […]
Are globular clusters in the Milky Way?
Are globular clusters in the Milky Way? Globular star clusters are known to be located mostly in the great spherical halo of the Milky Way. Spiral galaxies like our Milky Way contain stars, gas and dust, mostly organized into a flat disk containing the spiral arms, but with the addition of a more rounded bulge […]
What is the formula to find the mass?
What protects the cell and is selectively permeable?
What protects the cell and is selectively permeable? A selectively permeable (sometimes called semi-permeable) membrane allows some molecules across but not others. JOB: The cell membrane controls what enters and exits the cell and thus protects the cell. How do organelles help keep the cell alive? Core organelles are found in virtually all eukaryotic cells. […]
What are the limitations of capture-recapture?
What are the limitations of capture-recapture? Mark / Recapture Techniques These techniques have a number of limitations: The animal usually needs to be captured to be marked, which may injure it, or alter its behaviour pattern. The mark used may harm the animal – for example a dot of a particular paint may turn out […]
Do fires raise soil pH?
Do fires raise soil pH? The impact of fires on vegetation and wildlife is obvious. Nutrient levels and soil organic matter both increase after fire. Spanish research showed a significant increase in soil pH, carbon and nutrients immediately after a prescribed grass fire. How is soil affected by fire? The most dramatic effect of a […]
How big asteroid that killed the dinosaurs?
How big asteroid that killed the dinosaurs? It was tens of miles wide and forever changed history when it crashed into Earth about 66 million years ago. The Chicxulub impactor, as it’s known, was a plummeting asteroid or comet that left behind a crater off the coast of Mexico that spans 93 miles and goes […]
What keeps the moon moving in a circular motion?
What keeps the moon moving in a circular motion? Gravitational attraction provides the centripetal force needed to keep planets in orbit around the Sun and all types of satellite in orbit around the Earth. The Earth’s gravity keeps the Moon orbiting us. It keeps changing the direction of the Moon’s velocity. What changes continuously in […]