cones are specialized reproductive structures of the sporophyte. Each cone consists of several âscalesâ arranged around an axis. Each scale is a sporophyll that will bear the spores of the sporophyte generation. An ovulate cone has many hard, radiating scales, each bearing a pair of ovules. Pollen cones are generally much smaller than ovulate cones; they contain many sporangia, each of which makes numerous haploid spores by meiosis. Male gametophytes (pollen grains) develop from the spores.
Bradycardia was defined as a heart rate less than 60 beats per minute when textbooks asserted that the normal range for heart rates was 60â100 BPM. The normal range has since been revised in textbooks to 50â90 BPM for a human at total rest.
A Resting Heart Rate anywhere in the range of 60 - 90 is considered in the normal range. Your Heart Rate will fluctuate a lot depending on such factors as your activity level and stress level. Resting Heart Rate anywhere in the range of 60 - 90 is considered in the normal range. Your Heart Rate will fluctuate a lot depending on such factors as your activity level and stress level.